Improvement in heat-governors or draft-regulators



F. E. CHATABD, Jr.

Heat Governors or Draft Begulatws r N0. 138,736, Pa tented May 13,1873.

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" rnn STATES PATENT QFFICE.

FERDINAND E. OHATARD, JR, OF BALTIMORE, MARYLAND.

I IMPROVEMENT IN HEAT-GOVERNORS OR DRAFT-REGULATORS- Specificationforming part of Letters Patent No. 138,736, dated May 13, 1873;application filed February 13, 1873.

To all whom it may concern:

Beitknown that I, FERDINAND E. CHATARD, Jr., of Baltimore, in the countyof Baltimore and State of Maryland, have invented certain Improvementsin Draft-Regulators or Heat- Governors for Ovens, Stoves, and Hot-AirFurnaces, of which the following is a specification:

The first part of my invention relates to the draft-box, which isconstructed of tin or other material, of suitable form and properdimensions, according to the size of the furnace or stove. This box isopen on the face, and divided interiorly ator near the center by adiaphragm, thus forming an upper and a lower compartment. The lowercompartment is made to communicate by a pipe, or otherwise, with the ashbox or pit of the oven, furnace, or stove, so as to furnish air beneaththe fire; the upper compartment communicates by a pipe, or otherwise,with the dome of the oven, furnace, or stove, or with the smoke-pipe ofthe same, so as to send a current of air above the fire or directly intothe smoke-pipe. The open face of the draft-box is provided with asuitable damper-plate, which can completely close the opening andprevent air entering either above or below the fire, or, by being placedin certain positions, permit air to enter either into the lower or uppercompartments. The lower portion of the draft-box is provided interiorlywith a curved metallic plate of the same curve as that described by thelower portion of the damper when moving within the box. By this means noair can pass into the lower compartment even when the damper has passedwithin and consider-- ably beyond the central line, which is theposition of the damper when air is passing freely into the uppercompartment and above the fire. The upper compartment is provided on itsupper inside surface with a curved metallic plate nearly similar to theone just described, except that it follows the curve made by the upperportion of the damper in rotating, thus preventing air entering theupper compartment when the upper portion of the damper has passed withinthe center line, its position when admitting air into the lowercompartment. It will thus be seen that while the damper is moving so asto allow free entrance of air into the lower compartment, the curvedmetallic plate of the upper compartment closely fitting to the upperportions of the damper prevents air entering above the fire; the lowercurved plate acts similarly in preventing entrance of air into the lowercompartment when the damper is moved, so as to send the draft above thefire. These upper and lower curved plates may be attached to the upperand lower edges of the damper instead of to the box, and will producethe same effects.

The second part of my invention relates to the motor, by which motion iscommunicated to the damper. It consists of a small cylindrical or othershaped chamber open above but closed below. In the center of thischamber from below upward, and nearly to the level of the top of thechamber, passes a tube which communicates at its lower part with a tubeextending from and. communicating with a metallic airtight vesselhereinafter described. The space between the inside tube and the wallsof the chamber is filled with mercury or other fluid. Over the insidetube is placed a bell or cylinder, open below but closed above, ofsomewhat less diameter than the inside of the outer chamber. From theupper portion of this bell passes a rod of glass or metal, on which is arack to communicate its motion to a toothed quadrant or pinion on theaxis of the damper. or other fluid is placed, in the outer chamber,nearly to the level of the inner tube, and the bell is placed inposition, by forcing inside the bell, through the center tube, air orany, fluid motion upward, in the direction of the least resistance, isthe result. Any other usual mode of converting rectilinear into circularmotion may be used instead of the rack and pinion.

The third part of my invention relates to the construction and locationof the vessel which furnishes the motive power to the motor justdescribed. It consists of a simple or ornamented air-tight metallic tubeor vessel, of proper size and convenient shape, which is placed withinthe hall, parlor, or any other convenient room of the house 'or withinthe oven. When the air or fluid within this tube or vessel becomesheated to a certain temper- When the mercury ature by the air of theroom or oven, it necessarily expands, and this expansion is utilized bymeans of the motor hereinbefore described, or some equivalent device, tocommunicate motion to the damper, as above described.

The object and nature of this invention is to regulate or govern thetemperature of a house, store, or building by connecting, by a suitablemechanism or motor, a draft bOX, which can, as required, supply aireither above or below the fire of a furnace or stove, with a metallicair-tight vessel placed within any part of the building the temperatureof which part may be considered a standard. The variations oftemperature within this room or part of the building act upon the airwithin the metallic vessel, and the expansion or contraction resultingis employed, by means of the motor apparatus, to open or close thedampers.

In the working of this draft-regulator the expansion of the contents ofthe air-tight vessel or tube is first employed to cut off the draftbelow the fire by closing the open face of the lower compartment. Shouldthe heat of the room or oven still increase beyond the standardtemperature, all additional expansion will result in opening the uppercompartment of the draft-box, and the draft will pass above the fire ordirectly into the smokepipe.

Description of Drawing.

Figure 1 is a side view of the draft-box A A, showing the pipes B andO--O communicatin g with the ash-box or below the fire, while B extendsfrom the upper compartment to the smoke-pipe or above the fire. D is themotor, with the rod and rack E engaging the toothed pinion F on the axisof the damper. G is the pipe which extends from the motor D to theairtight vessel H, 'placed in a room of the house or in the oven. K isthe damper-plate which serves to close the open face of the draft-box,and is here seen in position admitting air freely into the lowercompartment 0 and pipe (3, Fig. 2. At the upper portion of the draft-boxis seen a lever, L, with a movable weight, by which the downwardpressure of the bell T, Fig. 3, is increased, and hence an increasedpower with proportional increase of temperature is required to move itupward, so as to cause the damper to close the lower compartment. Fig. 2is a vertical section through the draft-box, showing the diaphragm M,which divides the interior into an upper and a lower compartment N andO; the damper K in position admitting air into 0, no air can enter theupper compartment N, owing to the upper curved plate I closely fittingthe upper edge of the damper. R is the lower curved plate. Fig. 3 is avertical section of the mo tor D and metallic air-tight vessel H, seenin Fig. l; the tube G, which forms the communication between the bell Tand the vessel H, is likewise shown.

In the operation of this heat-governor or draft-regulator, the metallicair-vessel is filled with air, at a given temperature, and then placedin that part of the building the temperature of which is to govern orregulate the degree of heat of the hot-air chamber of the furnace orstove which is employed to warm the building; for, if the temperature ofthis part varies according to changes in the outside atmosphere, it isevident that the variations of temperature of the hot-air chamber shouldcorrespond. The variations of temperature in the place where theair-vessel is situated must produce either expansion or contraction ofair within the vessel, and this expansion or contraction causes anupward or downward movement of the bell or inverted cylinder of themotor apparatus, for the two are in communication through afine tube.The upward motion, the result of expansion or increase of temperature,causes the damper to move so as to open communication between the uppercompartment of the draft-box and the outside air, allowing the draft toenter above the fire. The downward motion, the result of contraction ordiminished temperature, opens the lower compartment and permits thedraft to enter below the fire. Thus the variations of temperature actingon the metallic air-vessel are recorded at the draftbox by the openingor closing of draft; and, as a result, the temperature of the hot-airchamber of the furnace or stove is governed, and can never vary muchfrom the proper degree of heat required to keep the building at a fixedpoint of temperature.

I claim as my invention- 1. The draft-box AA with its two compartments Nand O, and damper-plate K, when constructed and arranged to operate ashereinbefore set forth.

2. The motor D with its bell T and pipe G, when constructed and arrangedto operate as hereinbefore set forth.

.3. A metallic air-tight tube or vessel, H, when placed within the ovenor within any of the rooms of a building to be kept at a standardtemperature,-which tube or vessel, by the expansion of its contents,communicates motion by suitable device, substantially as set forth, to adamper to regulate the draft and heat of an oven, furnace, or stove.

FERDINAND E. GHATARD, J R.

Witnesses:

S. A. MORSE, GEO. M. CAFFRAY.

